" CVVs, CVV2s, CVCs, and Indent CVCs are 3-digit Card Verification Values or Card Verification Codes that are all calculated using the same CVV algorithm. These values are required by payment systems such as Visa and MasterCard to authenticate their credit or debit cards. Different names are used to refer to the values depending on the particular payment system, the location of the value on the card, and the parameters passed to the CVV algorithm.

To calculate a 3-digit CVV, the CVV algorithm requires a Primary Account Number (PAN), a 4-digit Expiration Date, a 3-digit Service Code, and a pair of DES keys (CVKs)."

I have no idea how true this information is. I would have thought that it would be similar to a secret PIN number where there is no correlation between the PIN and any account information.